Fix issue 6751: epoch date formats '%H:%M:%S' as 'undefined' - #6752

Fix issue 6751: epoch date formats '%H:%M:%S' as 'undefined'#6752

archmoj merged 2 commits into

plotly:masterplotly/plotly.js:masterfrom

adamjhawley:fix-undef-date-hoveradamjhawley/plotly.js:fix-undef-date-hoverCopy head branch name to clipboard